A magnetic resonance imaging apparatus is designed to measure the density distribution, the distribution of the relaxation time and the like of nuclear spins (hereinafter referred to as spins) in a desired region of an object to be examined, utilizing a NMR phenomenon, and to display an image of any cross-section of the object according to measurement data obtained as a result thereof. Such a magnetic resonance imaging apparatus has been increasingly used in surgery and for other therapies.
For use in surgery or other therapies, there is a magnetic resonance imaging apparatus of the open type, which is constituted of magnets of the vertical magnetic field type (opposing type). The magnets of the vertical magnetic field type do not make the object feel trapped or closed in, in comparison with magnets of the horizontal magnetic field type, that is, magnets having a cylindrical shape. Further, it also gives a released feeling to the operator of the apparatus. Therefore, a magnet of the vertical magnetic field type is employed.
However, sufficient consideration has not been given to the operator performing the operation or therapy while observing the image of a lesion in real time in a magnetic resonance imaging in apparatus having the above-described structure.
The object of the present invention is to provide a magnetic resonance imaging apparatus which can perform imaging, to detect a signal, and to perform reconstruction, display, and updating of an image, without deteriorating the real-time nature of the display, even in the case where a magnetic resonance imaging apparatus is used in an operation or the therapy.